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Full text of "Text Book Of Mechanical Engineering"

APPENDIX V.

(SIXTH    EDITION.)

CHAPTER I.

Pp. 34 and 785. Moulding Machines.óBy the use of the
hydraulic machine shewn in Fig. 902, which is made by Messrs.
Bopp & Reuther of Mannheim, the pressing of the sand is per-
formed simultaneously in both moulding boxes, and the removal
of the latter effected at one operation, thus accelerating the
work.

The hydraulic cylinder G contains a ram F, which supports a
table u carrying the lower box E, and the constant pressure in
cylinders s s balances the dead weight. The pattern plate A, to
which are attached the two half-patterns B and c, is run into
position along the rails shown. The upper box D is supported
on a frame which can slide on vertical rods Q Q, and is connected
to the ram F by the piston rod H, the crosshead j, and the ropes
passing round the pulleys M N K L; so it follows that the raising
of E will lower D, and vice versd.

The pattern plate A being admitted, the boxes are filled with
sand, and a suitable presser block placed at T. The pressure
water is next let into the ram, and as E is raised to meet the
plate, D is simultaneously lowered, after which E, A, and D rise
together till they reach the block T; thus putting the required
compression on the sand. The valve R being now opened to
exhaust, the pressure is removed, and the ram again falls, lowering
the pieces E, A, and D : together at first. The moment, however,
that E detaches itself from plate A, so also does D begin to
rise; and when they all take the positions shewn, the boxes
may be removed and the operations repeated with a new pair of
boxes,